'use strict';

/**
 * map_reduce_merge.js
 *
 * Generates some random data and inserts it into a collection. Runs a
 * map-reduce command over the collection that computes the frequency
 * counts of the 'value' field and stores the results in an existing
 * collection on a separate database.
 *
 * Uses the "merge" action to combine the results with the contents
 * of the output collection.
 *
 * Writes the results of each thread to the same collection.
 */
load('jstests/concurrency/fsm_libs/extend_workload.js');         // for extendWorkload
load('jstests/concurrency/fsm_workloads/map_reduce_inline.js');  // for $config

var $config =
    extendWorkload($config,
                   function($config, $super) {

                       // Use the workload name as the database name,
                       // since the workload name is assumed to be unique.
                       var uniqueDBName = 'map_reduce_merge';

                       $config.states.init = function init(db, collName) {
                           $super.states.init.apply(this, arguments);

                           this.outDBName = db.getName() + uniqueDBName;
                       };

                       $config.states.mapReduce = function mapReduce(db, collName) {
                           var outDB = db.getSiblingDB(this.outDBName);
                           var fullName = outDB[collName].getFullName();
                           assertAlways(outDB[collName].exists() !== null,
                                        "output collection '" + fullName + "' should exist");

                           // Have all threads combine their results into the same collection
                           var options = {
                               finalize: this.finalizer,
                               out: {merge: collName, db: this.outDBName}
                           };

                           var res = db[collName].mapReduce(this.mapper, this.reducer, options);
                           assertAlways.commandWorked(res);
                       };

                       $config.setup = function setup(db, collName, cluster) {
                           $super.setup.apply(this, arguments);

                           var outDB = db.getSiblingDB(db.getName() + uniqueDBName);
                           assertAlways.commandWorked(outDB.createCollection(collName));
                       };

                       $config.teardown = function teardown(db, collName, cluster) {
                           var outDB = db.getSiblingDB(db.getName() + uniqueDBName);
                           var res = outDB.dropDatabase();
                           assertAlways.commandWorked(res);
                           assertAlways.eq(db.getName() + uniqueDBName, res.dropped);
                       };

                       return $config;
                   });
